Interpreter for an uncommon Lisp:
https://sr.ht/~ft/StreetLISP/
mentioned on the 9fans mailing list https://marc.info/?l=9fans&m=175157062515466&w=2

There are no plans to turn this into Yet Another Scheme, which are already plenty to choose from. When it comes to general development directions, StreetLISP is moving towards being somewhere in between Common Lisp and Scheme, yet not striving to fit any specific standard. The goals are certain level of minimalism and less typing, useful standard library, good Unicode support, portability and interfacing with C of both POSIX-like operating systems and Plan 9. Eventually, hopefully, there will be experiments in cooperative/multithread computations with Erlang-style message passing between "processes".